Keel bolts condition
- Thread starter Yannis
- Start date
Tranona
Well-known member
Nothing out of the ordinary. The backing plates seem to be mild steel and have got rust on them from bilge water. No signs of serious corrosion, so cleaning up and painting would be a good idea. The bolts themselves (actually studs screwed into the keel) will almost certainly be as good as the day they were installed. Much more important to check the hull/keel joint externally to ensure the seal is still sound as this is the only way water can get in to do any harm to the studs.
What boat is it?
What boat is it?
Yannis
New member
Thank you for the comment!! It is a Jeanneau Sun Odyssey 34.2
AndrewB
Well-known member
As Tranona says. In fact quite good for a boat that is perhaps 20 years old, though it does hint that water regularly gets in the bilge. But to check properly you need to withdraw one or two and inspect. It's fairly standard practice. If you are having the boat surveyed, ask for this to be done.
eilerts
Member
Don't forget to ask if it has been grounded, and how was it repaired. I see a crack in base between the bolts and the stiffener in picture 2. It should not be there
Yannis
New member
Thank you. I will do so.
Yannis
New member
Thanks a lot. Good that you spotted.
Fr J Hackett
Well-known member
The crack doesn't seem to propagate into the limber hole so maybe just the edge of the last piece of glass that was a little short.
Yannis
New member
Thanks for you comment!!
KompetentKrew
Well-known member
Yes, I think something like this too. I'm sure I have similar on my boat and it seems fine.
+1 to the comments that this is perfectly normal. The rust is on the surface and will affect the strength of it not one bit. If you were hypothetically to cut the nuts and bolts in half you would find them to be 99% shiny metal by cross-sectional area.
jwilson
Well-known member
I would disagree that to ".... withdraw one or two and inspect" is fairly standard practice. That looks like the bilge of a 2000-ish Jeanneau and the keelbolts look OK to me for that age. Unless there is something other than a bit of surface rust I can see no reason to do anything more than clean them up and paint them.
dombuckley
Well-known member
+1 The crack seems to coincide with a change in the surface texture, so most likely either this or the edge of the flocoat.
Jeanneau Sun Odyssey 34.2 keelbolts are actually steel studs cast into the keel. You cant withdraw them individually: the only way to fully inspect will be to drop the entire keel. Short of this, the best gauge of their condition is to check for any additional rust streaks on the exterior of the hull/keel joint when the boat is lifted.
chrisD
Member
is withdrawing a keel bolt really fairly standard? I have never known a surveyor suggest it on boats I have bought or sold. If a buyers’ surveyor wanted to start attacking the bolts on my boat I would be rather concerned they might do more harm than good.
AndrewB
Well-known member
This was done at the surveyor's suggestion on my present boat (and was also done on an earlier boat I owned, though not in that case at the point of sale). A photo of one of them is below. It is in fact a stud (see Dombuckley's comment above), but the surveyor's opinion was that they ought to turn out, and that proved correct.¹
There was concern because of the black oily water in the bilge when surveyed - you can see the state of the bilge in the pic. However the bolt is in good condition. Of course the seller's permission was needed for this: he, like me, accepted it was fairly standard practice and had no problem as long as it was made good. Care was taken not to use excessive pressure on the bolts in order to withdraw them.
¹ P.S. I'm struggling to remember why. It may have been that he assumed the nut would have been welded to the stud after fitting.
Last edited:
jwilson
Well-known member
Like many others I tend to use the word "keelbolt" although I know that almost all of them are actually studs threaded into iron keels. Lead keels are usually differently attached.
Although a very few surveyors do routinely suggest that keelbolts be drawn to check condition, almost always when this is done, often at considerable expense, it is really rare for anything actually to be found wrong with the hidden thread. Some years ago the ISAF investigated keel losses, and they found 72 cases of boats losing their keels. Only three were attributed to keel bolt failure . Going back to the OP's question, there really looks nothing unusual about his studs/keelbolts.
The above applies to GRP boats, wooden boats quite often had corrosion in the internal areas of steel keelbolts/studs.
Although a very few surveyors do routinely suggest that keelbolts be drawn to check condition, almost always when this is done, often at considerable expense, it is really rare for anything actually to be found wrong with the hidden thread. Some years ago the ISAF investigated keel losses, and they found 72 cases of boats losing their keels. Only three were attributed to keel bolt failure . Going back to the OP's question, there really looks nothing unusual about his studs/keelbolts.
The above applies to GRP boats, wooden boats quite often had corrosion in the internal areas of steel keelbolts/studs.
vyv_cox
Well-known member
This is a response to a similar post made by a member named brccd many years ago. The bolts are from a 32 year old Beneteau that at the time were bolts rather than studs and made from 8.8 carbon steel. As can be seen in the photo the heads were rusty due to seawater in the bilge but the threads were in good condition.
